Electrostatic generator electrode-centering and seismic-isolation system for flywheel-based energy storage modules

Abstract

Robust electro-static (ES) device embodiments, with application to energy storage flywheels as an example, are described that provide reliable, high-efficiency operation in the presence of thermal and mechanical perturbations, as well as seismic events. Electro-static generators and motors, when augmented with magnetic bearings, passive three-dimensional stabilization techniques and dynamic touch-down bearings, enable robust performance in the face of these environmental concerns, as well as efficient operation during typical operational sequences, including spin-up and steady-state modalities.

I claim: 
     
       1. An apparatus, comprising:
 an open cylindrical rotor having a central axis of rotation and an inner surface; 
 a first support structure that is stationary relative to said rotor; 
 a first annular element having its outermost edge attached to a first location of said inner surface of said rotor; 
 a second annular element attached to said first support structure, wherein said second annular element is positioned in proximity to said first annular element, wherein at least one of said first annular element and said second annular demerit is configured to magnetically attract the other of said first annular element and said second annular element; 
 a second support structure; 
 an axial stabilizer selected from the group consisting of a first triplet array and a second triplet array, wherein said first triplet array comprises: 
 a first magnetic annular element attached to a second location of said inner surface of said rotor; 
 a second magnetic annular element attached to said second support structure; and 
 a third magnetic annular element attached to said second support structure, wherein said second magnetic annular element and said third magnetic annular element are positioned on opposite sides, one to another, of said first magnetic annular element and both magnetically repel said first magnetic annular element, and wherein said second triplet array comprises: 
 a first magnetic annular element attached to said second support structure; 
 a second magnetic annular element attached to a third location of said inner surface of said rotor; and 
 a third magnetic annular element attached to a fourth location of said inner surface of said rotor, wherein said second magnetic annular element and said third magnetic annular element are positioned on opposite sides of said first magnetic annular element and both magnetically repel said first magnetic annular element; 
 a base and at least one compression spring attached to and located between said second support structure and said base; 
 a guide tube fixedly attached to said base; 
 a guide shaft fixedly attached to said second support structure, wherein said guide tube is configured to receive said guide shaft; and 
 a passive stabilizer selected from the group consisting of a third triplet array and a fourth triplet array, wherein said third triplet array comprises: 
 a first annular magnet element having edge fixedly attached to a fifth location of said inner surface of said rotor; 
 a second annular magnet element having an edge fixedly attached to a sixth location of said inner surface of said rotor; and 
 a first inductive element fixedly attached to said second support structure, wherein said first inductive element is located between said first annular magnet element and said second annular magnet element, and wherein said fourth triplet array comprises; 
 a third annular magnet element having an edge fixedly attached to said second support structure; 
 a fourth annular magnet element having an edge fixedly attached to said second support structure; and 
 a second inductive element having an edge fixedly attached to a seventh location of said inner surface of said rotor, wherein said second inductive element is located between said third annular magnet element and said fourth annular magnet element. 
 
     
     
       2. The apparatus of  claim 1 , wherein said second support structure comprises a bearing support structure having at least one spherical element, said apparatus further comprising an annular bearing element fixedly attached to said rotor, wherein said annular bearing element comprises an annular conical slot facing said central axis of rotation, wherein a portion of said at least one spherical element is positioned within said slot. 
     
     
       3. The apparatus of  claim 2 , wherein when said rotor is at rest, said at least one spherical element will be in contact with said annular bearing element, wherein as said rotor is spun up from rest, said at least one spherical element will reach a speed wherein it will no longer make contact with said annular bearing element. 
     
     
       4. The apparatus of  claim 1 , further comprising a bearing support structure having at least one spherical element, wherein said bearing support structure is fixedly attached to said second support structure, said apparatus further comprising an annular bearing element fixedly attached to said rotor, wherein said annular bearing element comprises an annular conical slot facing said central axis of rotation, wherein a portion of said at least one spherical element is positioned within said slot. 
     
     
       5. The apparatus of  claim 4 , wherein when said rotor is at rest, said at least one spherical element will be in contact with said annular bearing element, wherein as said rotor is spun up from rest, said at least one spherical element will reach a speed wherein it will no longer make contact with said annular bearing element. 
     
     
       6. The apparatus of  claim 1 , wherein said first annular element together with said second annular element comprise a configuration selected from the group consisting of (i) wherein said first annular element is a ferromagnetic material and wherein said second annular element is a magnet (ii) wherein said first annular element is a magnet and wherein said second annular element is a ferromagnetic material, (iii) wherein said first annular element is a ferromagnetic material and wherein said second annular element is a Halbach array, (iv) wherein said first annular element is a Halbach array and wherein said second annular element is a ferromagnetic material and (v) wherein said first annular element is a Halbach array and wherein said second annular element is a Halbach array. 
     
     
       7. The apparatus of  claim 1 , wherein the net stiffness of each said at least one compression spring is smaller than the effective stiffness of said triplet array. 
     
     
       8. The apparatus of  claim 1 , wherein said apparatus is a flywheel based electrostatic (ES) motor/generator. 
     
     
       9. A method comprising:
 providing the apparatus of  claim 1 ; and 
 rotating said rotor.